Apparatus for coining metal parts



y 8, 1956 G. A. LYON 2,744,426

APPARATUS FOR COINING METAL PARTS Original Filed Oct. 26, 1944 4 Sheets-Sheet l l3 l6 m [6d 30 a M 12 74 K 26 28 7 EVEN/Ur" 62-04 0:- fl; e527 [rowy 1956 e. A. LYON 2,744,426

APPARATUS FOR COINING METAL PARTS Original Filed Oct. 26, 1944 4 Sheetsdheet 2 I24 ,2} 42 $1" 7 W Hill g v 4 lei 30 /54 /4 W 4 \Wll w 62-020: /71. eser L e/v y 3, 1956 G. A. LYON 2,744,426

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May 8, 1956 G. A. LYON APPARATUS FOR COINING METAL PARTS Original Filed Oct.. 26, 1944 4 Sheets-Sheet 4 &

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m 4 w 1 6 3 N MA I, n r V E W E E 4 r 9 w w 1 \6 n E a \w .n l 0 I a a \d 6 I t ,4, 7 -m m u b N w :1 9 m 6 w u United States Patent APPARATUS FOR COINING METAL PARTS George Albert Lyon, Detroit, Mich.

Continuation of abandoned application Serial No. 560,488, October 26, 1944. This application December 28, 1949, Serial No. 135,451

2 Claims. (CI. 78-60) This invention relates to a method of and apparatus for forming rounded blanks or articles from square, rectangular or other straight edged pieces of cold malleable metal stock such as may be cut, sheared or punched without waste contiguously from a flat slab or sheet of the metal.

The present application is a continuation of my application Serial No. 560,488, filed October 26, 1944, now abandoned.

In the conventional fabrication of drawn metal articles such as shell casings from relatively heavy flat metal stock, the usual practice has been to cut out round blanks from a fiat sheet of metal, and to utilize these round blanks as starting material forthe fabrication of the ultimately desired metal article. This conventional practice involves the scrapping of all the metal contained in the punched-out network of metal remaining from the original sheet of metal from which the round blanks have been cut.

It is therefore an important object of the present invention to provide an improved method of and apparatus for fabricating by cold working without any waste of stock rounded perimeter metal articles from angular blanks cut from flat cold-malleable metal stock.

Another object of the present invention is to provide improved method of and apparatus for cold working or coining cold-malleable metal blanks of angular outline and fiat faces into rounded perimeter and formed face.

A further object of the invention is to provide a method of and means for utilizing the material from the corners of an angular flat cold-malleable metal blank by redistribution in the body of the blank.

Still another object of the present invention is to provide a method of and means for cold working an angular fiat cold-malleable metal blank from angular flat shape to rounded perimeter formed-face shape in one continuous reshaping and coining process.

Yet another object of the invention is to provide improved apparatus for reshaping a rectangular metal blank.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings, in which:

Figure l is a horizontal cross sectional view taken along the line 1-1 of Figure 2;

Figure 2 is a vertical cross sectional view, with parts shown in elevation, of die apparatus according to the present invention equipped for lateral compression and subsequent coining of a straight edged metal blank with the working parts in the position assumed at the beginning of the forming operation;

Figure 3 is a cross sectional view similar to Figure 1 taken along the line llI--III of Figure IV but showing the die apparatus with the working parts in the position assumed at the end of the lateral blank compressing step;

Figure 4 is a cross sectional view similar to Figure 2 but showing the die assembly with the working parts in "ice the position assumed at the end of the lateral blank compressing step;

Figure 5 is a view similar to Figures 2 and 4 but showing the dieassembly with the working parts in the position assumed at the end of the coining step carried out on the laterally compressed metal blank;

Figure 6 is a fragmentary view similar to Figure 5,

, showing die apparatus including a coining die of some what different configuration;

Figure 7 is a plan view of a blank as shaped in the die assembly of Figure 6;

Figure 8 is a plan view of a blank as shaped in the die apparatus of Figures 1 to 5;

Figure 9 is a vertical cross sectional view, with parts shown in elevation, of another die assembly equipped with means for laterally compressing and concurrently shaping the broad faces of a straight edged metal blank, with the working parts in the position assumed at the beginning of the lateral compression step; and

Figure 10 is a view similar to Figure 9 showing the working parts in theposition assumed at the end of the lateral blank compressing step.

According to the present invention, square, rectangular or other angularly edged blanks after being cut, sheared or punched contiguously'from suitable fiat cold-malleable metal stock are compressed without application of any heat radially inwardly into rounded outline by pressure exerted against the corners. Then, while maintaining the rounded blanks continuously within the rounded perimeter, the blanks are coined or squeezed Without the addition of any heat and by cold flowing the material derived by displacement from the corners or derived from other portions of the blank to reshape a broad face of the re spective blanks; or the material displaced by the marginal reshaping of the respective blanks may be directly and concurrently with the marginal reshaping flowed into a face configuration. It is to be understood that the entire reshaping of the blanks is accomplished as an economical, continuous process on each blank without any necessity for transferring the blank from one die to another or other intermediate handling of the blank, and Without application of heat at any point in. the process, but at all times relying on the cold-malleability of the material worked on. The metal displaced from the corners of the blank is flowed substantially without or with only very slight interruption into its redistributed final location in the formed blank.

For this purpose I have provided die apparatus including, in combination with a suitable power operated press having a bed and a reciprocable crosshead or piston, a plurality of die members arranged about a central point on the press bed for inward radial movement effected by a corresponding numberof wedge or cam members mounted on the crosshead or piston of the press. The die members have inner working faces in the form of segments of the desired rounded outline, At the inward stroke of the die members they complementarily effect a lateral compression and rounding off of an angularly edged blank inserted therebetween. Suitable guide means are also provided for maintaining proper registration between the press head or piston and the press bed, as well as for maintaining proper alignment of the die members in their radial movement over the press bed. Coining die means mounted on the crosshead or piston of the press cooperates with the die members for reshaping broad faces of the rounded off blanks.

Reference is made to Figures 1 to 5, in which the numeral 10 indicates generally a die assembly according to the present invention including a die assembly square press bed 11 and a die carrier 12 mounted on the crosshead or piston (not shown) of a power operated press (not shown) for reciprocal movement to and from the press bed 11. To maintain proper alignment between the press bed 11 and the die carrier 12, erect guide pins 13 are mounted in upstanding octagonal bosses 11a formed in each corner of the square press bed 11. Each guide pin 13 is re ceived in sliding engagement by bushings 14 fitted in the lower ends of vertical apertures 12a in depending bosses 12b formed on the underside of the die carrier 12 and alined with the press bed bosses 11a.

A plurality, herein shown as four, somewhat elongated die members 16 having inner terminal working faces 16a in the form of circle segments are arranged about the center of the press bed 11. More particularly, two pairs of die members 16 are provided, each pair being aligned in opposed relationship diagonally of the press bed 11. The side walls of the die members 16 taper away, as at 16b, from the inner working surfaces 16a at an anglc of 135 to permit mutual abutment at the end of the radial inward stroke of the die members 16, as shown in Fig ure 3. The outer ends of the die members 16 are tentrally recessed as at 16c and the upper orifice of this recess is beveled or flared toward the working face 16:! as at 16d. Blocks 18 of rectangular horizontal and vertical cross section are interposed between the bosses 11a and the outer ends of the die members 16. These blocks 18 confront flat faces of the bosses 11a and form hearing abutments for driving wedge or cam fingers members 20 mounted on the underside of the die carrier 12 in registration with the recesses 160. The wedge or cam members 20 have a greater horizontal cross sectional area than the bottom area of the recesses 160 but, having their inner sides terminally beveled or tapered as at 20a are able to enter the recesses 16c to effect, on downward movement of the die carrier 12, an inward radial movement of the die members 16, due to a camming or a wedging action at the surfaces 200 and 16b, outward movement of the bearing blocks 18 being resisted by the bosses 11a. The die members 16 are thus displaced longitudinally radially inwardly from the position shown in Figure 1 to that shown in Figure 3.

For guiding the radial movement of the die members 16, an upstanding guide block 22 is anchored to the press bed 11 on each long side of each die member 16, each such guide block having a keying rib or tongue 22:: fitting in a corresponding guide groove 162 in the respective sides of the die members.

The underside of each die member 16 is formed with a longitudinal recess 16f opening on the inner or forward working face 16a. Pairs of coiled springs 24 are positioned in each of said recesses 16 for exerting an outward radial pressure on the outer or rear wall defining the recess 16 to urge the respective die members 16 apart into the retracted position shown in Figure 1. An abutment for the inner ends of the springs 24 is provided by a square spider 26 of a thickness corresponding to the depth of the recess 16 and arranged on the press bed 11:: centrally with respect to the die members 16. The spider 26 has four arms 26a that enter the recesses 16 centrally and serve as spacers to keep the coil springs 24 apart.

The press bed 11 is centrally apertured as at 111') and the spider 26 is likewise formed with a registering central aperture 26b. A piston 28 reciprocable by a rod 29 fits slidably within the spider aperture 26b and forms the bottom of a die chamber whose sides are defined by the working faces 16a of the die members 16 when the latter are in their fully protracted blank-shaping relationship.

A plunger coining die 30 is centrally mounted on the underside of the die carrier 12. In the present instance, the working face of the die 30 is formed with a shallow circular cavity or recess 30a connected to atmosphere at the upper outside of the die carrier 12 by an air vent passage 30b. It will be noted that the coining die 39 is shorter than the driving wedge or cam members 20, so that on downward reciprocation of the die carrier 12, the

drive members will first move the die members 16 radially inward to effect lateral compression of a polygonal, in this instance square, blank 35 of cold malleable metal whose upper broad face will immediately after the radial compression be shaped by the coining die 30. The diameter of the coining die plunger is complementary for slidable cooperation within the well defined by the closed forming surfaces 16a.

Operation of the die assembly of Figures 1 to 5 is as follows. One of the angular blanks in cold state is first inserted between the inner working faces 16a of the die members 16, being laid flat on top of the piston 28, which provides a fixed coining position for the blank as shown in Figures 1 and 2. It will be observed that the die fingers 16 are substantially thicker than the blank 35 so that a substantial space remains between the top of the blank and the top of the die fingers. The die members 16 at this time are urged radially outwardly and apart from each other by the springs 24 abutting against the spider 26 and acting upon the outer walls of the bottom recesses 16] in the die members 16. The top of the piston 28 is held level with the top of the spider 26 and with the top of the recess 16 The wedge or cam members 26 have their depending ends barely within the flared orifices of the recesses 16c in the outer ends of the die members 16. When, as shown in Figures 3 and 4, the die carrier 12 is reciprocated downwardly, the cam or wedge members 20 penetrate further into the recesses 16c ahead of the entry of the coining die 30 into the space between the inner working faces 16a of the die members 16. The straight outer surface of the cam members 20 abut against the bearing blocks 18 which in turn contact flat faces of the bosses 11a, so that on entry of the wedge members 20 into the constricted portion of the recesses 16c, the die members 16 are moved radially inward due to the camming action at the beveled terminal surfaces 20a of the wedge members 20 and the outwardly flared surfaces 16d formed in the die members 16. This radial inward movement of the die members 16 takes place against the action of the coil springs 24, which are thereby compressed. When the beveled terminal portions of the wedge members 20 have passed the surfaces 16d and entered into the restricted portions of the recesses 160, the tapering side walls 16b of the various die members abut mutually and the inner working faces 16a complementarily define a circular space, as shown in Figures 3 and 4.

As shown in Figures 3 and 4, the result of the inward movement of the die members 16 is to round off the corners of the blank 35 and to displace the material of the corners radially inwardly, causing the adjacent marginal portions of the blank to bulge upwardly.

Further downward movement of the die carrier 12 causes the coining die 30 to travel on down slidably within the die well provided by the cooperating surfaces 16a to impinge upon the top of the radially compressed blank 35, and while the latter is held within the perimeter of the radial compression, to compress the blank between the top of the piston 28 and the working face of the coining die 30. As a result, the marginal metal between the corners of the original blank is caused to flow outwardly and/or peripherally into perfect conformance with the inner working faces 16a of the die members 16 where the original perimeter of the blank was shy of enabling full conformance to the encompassing die assembly wall at completion of the radial compression. At the same time, the corner marginal bulges are redistributed from the upper face of the blank and metal is caused to flow inwardly to form a central bulge. Air trapped in the cavity 30a escapes through the vent 30b and thus relieves the coining die of resistance, avoids heating of the die assembly and prevents air pocketing of the surface of the formed blank due to air compression in operation of the die 30.

The completed blank is indicated in Figures 5 and 8 by the reference numeral and includes a relatively thinner marginal portion 46aand a Central bulge 40b. Such a round, marginallythin centrally-bulged blank is especially uesful for drawing relatively heavy-bottomed cupshaped articles or shells such as'ord'nance shell" casings.

After the original angular blank 35 has thus been shaped into the rounded blank 40, the die carrier 12 is reciprocated" upwardly and the coining die 30 as well as the wedging or camming members 20 are moved out of contact with the die member16, which are then spread apart by the action of springs 24, thus returning'the assembly to the position shown in Figure 1. At this time, the rod 29 may be actuated to displace the piston 28- upwardly for raising the rounded coined blank 40 from between the die members 16 for manual or other removal. The piston 28 is then dropped down to the position shown in Figure 2 and another cycle of operation maybe carried out with another angularly edged blank.

It will be noted that the coining die 30 is formed with a horizontal crosssectional area corresponding to the area of theflspaceqenclosed by the inner working faces 16a of the die'members 16 when the'latter are at the end of their inward stroke. The die members 16 thus perform the double function of laterally-compressing therebetween the original square blank by radial inward movement and thereafter, while stationary, acting as the female half of a die assembly wherein the coining die- 30 forms the male member. in the performance of the continuous cold' working method of the present invention.

" The methodsand-apparatusof the present invention are I also adapted for makingdisk-like blanks and articles having a relatively heavy or thick edge and a thin or recessed center portion. For this purpose, the apparatus shown in Figure 6 may be employed, which is constructed identically with the apparatus of Figures 1 to 5 except that the apparatus of Figure 6 has'a coining die plunger 50 provided with a lower working face having a central bulge or forming boss protrusion 50a. The blank coined in the apparatus of Figure 6 is designated in Figures 6 and 7 by the reference numeral 51 and includes a relatively heavy rim or raised edge 51a surrounding a central recess 51b. Such a blank is particularly suitable for further fabrication into wheels having peripheral flanges, and the like.

Rounded blanks such as those shown in Figures 7 and 8 may also be die-formed from angular-edged metal pieces in a die assembly such as that shown in Figures 9 and 1.0 and there indicated generally by the reference numeral 60. This die assembly includes (like the apparatus of Figures 1 to 5) a square press bed 61 provided with corner bosses 61a and an upper carrier member 62 formed with depending corner bosses 62b vertically apertured at 62a and carrying bushings 64 receiving in sliding engagement erect guide pins 63 seated in press bed bosses 61a. The press bed 61 is formed with a central boss 61c and is centrally apertured at 61b to receive in sliding engagement a piston rod 69 carrying at its upper end a piston 68 operating in an upper counterbore seat cavity portion 61d of the aperture 61b which provides shoulders on which the under side of the piston 68 is supported. Wedge or camming drive finger members 70 depend from the underside of the die carrier 62 and have their inner surfaces terminally bevelled or tapered as at 70a for cooperation with abutment blocks 78 disposed between the bosses 61a and four die members 66 formed with their outer walls recessed at 66c and provided at the upper recess orifices with camming surfaces 66d.

The die assembly of Figures 9 and 10 also includes a vertically reciprocable ram or press head plunger 80 movable through a central aperture 620 in the die carrier 62 and having a tapering end portion 80a terminating in a working face formed, as shown, with a central shallow cavity or recess 80b although it could also be formed with a forming boss similarly as the die plunger 50 of Figure 6. The inner working faces 66a of the reciprocable die members 66 are formed on constricted or thinner inner end portions 66g on said die members- Note that at the end of the inward radial stroke of a die member 66, the constricted inner end portion 66g rests upon the upper surface of the piston 68. In the apparatus of Figures 9 and 10, no central spider is provided as in the apparatus of Figures 1 to 5, but instead the upstanding boss or flange 610 formed around the aperture 61!) provides an abutment for coil springs 74 disposed in bottom recesses 66 formed in the die members 66 and opening in the inside thereof outside the constricted portions 66g. Guide means (not shown) for the die members 66 may be provided similarly to the apparatus of Figures 1 to 5.

The ram die plunger 80 and the die carrier 62 may be operatively connected to a double acting press so adjusted that initially the ram 80 is brought down into exact contact with the top of the restricted inner ends 66g of the die members 66 and held there while the carrier 62 is reciprocated downwardly to force the die members 66 from the position'shown in Figure 9 into the position shown in Figure 10; This subjects an angularly edged blank 90 disposed therebetween to lateral pressure for rounding off the corners of the same and at the same time reforms the upper face of the blank by flowing redistribution of material of the blank.

The rounded out and reshaped-surface blank 90 may be raised from between the retracted die faces 66a by upward movement of the piston 68 for manual removal.

It will be noted that in the apparatus of Figures 9 and 10, I have provided a die cavity defined by a stationary lower member, an upper member moved into and out of a position maintained during the die forming operation, and a plurality of die members moving in opposite directions to compress laterally a straight-edged blank held against upward 'or downward movement between said upper and lower members. Further, the upper and lower die members act as guides for said plurality of die members that are reciprocated radially of the die cavity to effect the radial compression forming of the blank.

The die assemblies of Figures 1 to 6 are particularly adapted for shaping metals that are not hardened noticeably on repeated cold working, for instance, aluminum and aluminum alloys. The die assembly of Figures 9 and 10 is the preferred apparatus for shaping metals that are characterized by decided hardening on cold working, such as brass.

According to all forms of the present invention angular sided flat metal blanks which are cold-malleable are reshaped by rounding off the perimeter, redistributing corner material of the blank and reshaping at least one surface of the blank, all continuously and in one handling of the blank in a cold state, requiring no heating of the blank or the die structure in any phase of the process. Metal stock may be utilized that is thinner than the ultimate rounded, face-shaped completed blank. No metal is wasted, because the metal which would be wasted according to to the conventional processes involving initially punching out rounded blanks, is by the present invention utilized in building up the broad faces of the blanks. Therefore, the present invention effects not only substantial economy in material but also substantial economy in fabrication as a result of the novel continuous, cold working method employed in fabrication or shaping of the blanks.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

die members radially inwardly, a spider structure disposed above said bed and underlying the forward portions of the die members and having respective radiating arms substantially narrower than the respective die members underlying each of said die members in longitudinal centered relation, shoulder means on the spider at each side of each of said arms and facing rearwardly relative to the respective die members, each die member having shoulder means on its rear portion opposing the spider shoulders opposite thereto, respective pairs of compression return springs engaging endwise between the respective shoulders and shoulder means in the space under each of the respective die members and with the associated radiating arm maintaining the respective pair of springs separated and in balanced thrust relation to the shoulder means engaged thereby, said springs normally acting to return said die members radially outwardly to non-operating position, and means cooperating in spaced relation with the opposite sides of the respective arms to retain the respective pairs of springs against lateral displacement relative to the associated arms 2. In metal working apparatus, a press bed; a press head reeiprocable toward and away from said press bed; generally radially extending die members radially longitudinally reciprocably cooperative relative to a center over the press bed; upwardly projecting rigid individual bosses in spaced relation to the outer ends of the respective die members; the areas laterally between the bosses above the press bed providing an unobstructed perimeter for access to the die members; guide pins extending into said bosses and cooperatingin guiding relation with said press head; and mechanism for applying a thrust force to the outer ends of said die member for diriving the die members toward one another, comprising abutment means disposed solidly relative to the respective bosses in opposition to the adjacent outer ends of the respective die members, and wedging means carried by the press head and operatively cooperating with the abutment means and the respective outer ends of the die members for driving the die members inwardly during movement of the press head toward the press bed and for releasing the die members upon movement of the press head away from the press bed.

References Cited in the file of this patent UNiTED STATES PATENTS 125,376 Brown Apr. 9, 1872 221,102 Rowell Oct. 28, 1879 330,262 Richardson Nov. 10, 1885 334,255 Little Jan. 12, 1886 373,084 Miller Nov. 15, 1887 449,824 Pearson Apr. 7, 1891 492,739 Butts Feb. 28, 1893 803,071 Schoen Oct. 31, 1905 881,399 Hansen Mar. 10, 1908 1,883,079 Strickland Oct. 18, 1932 2,158,434 Schwartz May 16, 1939 

4. IN COMBINATION IN A DIE APPARATUS FOR SHAPING TO A PREDETERMINED PERIMETER METAL BLANKS WHICH DIFFER FROM SUCH PERIMETER, A PRESS BED, A PLURALITY OF RADIALLY MOVABLE ELONGATED DIE MEMBERS OF SUBSTANTIAL WIDTH SPACED A LIMITED DISTANCE ABOVE SAID BED, SAID DIE MEMBERS HAVING THEIR INNER ENDS COOPERATIVELY SHAPED AND RELATED TO RECEIVE A BLANK EDGEWISE THEREBETWEEN FOR COMPRESSING IT TO SAID PREDETERMINED PERIMETER, MEANS FOR DRIVING SAID DIE MEMBERS RADIALLY INWARDLY, A SPIDER STRUCTURE DISPOSED ABOVE SAID BED AND UNDERLYING THE FORWARD PORTIONS OF THE DIE MEMBERS AND HAVING RESPECTIVE RADIATING ARMS SUBSTANTIALLY NARROWER THAN THE RESPECTIVE DIE MEMBER UNDERLYING EACH OF SAID DIE MEMBERS IN LONGITUDINAL CENTERED RELATION, SHOULDER MEANS ON THE SPIDER AT EACH SIDE OF EACH OF SAID ARMS AND FACING REARWARDLY RELATIVE TO THE RESPECTIVE DIE MEMBERS, EACH DIE MEMBER HAVING SHOULDER 